Easy Sport .60 kits are no longer in production. The only difference between the two kits should be the size and weight of the finished plane; the Easy Sport .60 didn't vary from the .40-sized model with regard to structure or airframe features. The planes were similar enough that Great Planes used the same instruction manual for both kits, but obviously the build plans themselves were different:

http://manuals.hobbico.com/gpm/gpma0150-0152-manual.pdf

An Easy Sport .40 kit powered with an O.S. Max .50 SX would be a lot of fun to fly!